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DT A/0ACETIC ESTER                           95

The glycocoll ester and sodium nitrite are shaken together in
a separating funnel (250 c.c.) until the nitrite is dissolved, a
little water being added if necessary. Fifteen c.c. of ether are
poured into the funnel, and when the temperature has sunk to
about 5' , two or three drops of a ten per cent, sulphuric acid
solution are added. The mixture is now well shaken for a
minute and the aqueous layer drawn oft" into a flask standing in
ice whilst the yellow ethereal solution, separated as completely
as possible from water, is poured from the neck of the funnel
into a dry flask. The aqueous portion cooled to 5 is returned
to the funnel and the process is repeated five or six times with
fresh quantities of ether, a few drops of sulphuric acid being-
added each time before shaking, and the yellow ethereal layer
separated, until the ether is only slightly coloured.

The united ethereal extracts are shaken with very small
quantities of sodium carbonate solution until no more carbon
dioxide is evolved and the solution remains alkaline. The
ether solution is then thoroughly dehydrated over calcium
chloride over-night and the ether carefully i*emoved on the
water-bath, which should not be heated to boiling. When most
of the ether has been distilled off, the flask is taken from the
water-bath and the remainder of the ether removed by blowing
air over the surface of the liquid. Yield about 15 grams.

Properties.  Deep yellow liquid which explodes on boiling ;
but distils undecomposcd under diminished pressure.

Reactions. Add a drop of the diazoacetic ester to con-
centrated sulphuric acid. It decomposes explosively. Heat a
few c.c. of the ester in turn with water and alcohol. Nitrogen
is evolved with the formation of glycollic ester in the first case
and ethyl glycollic ester in the second.

Add an ethereal solution of iodine. Nitrogen is evolved and
iodacetic ester is formed. TIeat a little of the ester with
concentrated hydrochloric acid. Nitrogen is evolved and
chloracctic ester is formed. Gradually add five grams of the
diazoacctic ester to a solution of 8 grams of caustic soda